A wireless device in communication with a communication system can enter a low power or idle mode, for example, to conserve network resources as well as power storage on the wireless device. When the wireless device is in idle mode, the wireless device typically is not in continuous or active communication with the communication system. In order to notify a wireless device which is in idle mode of the arrival or availability of data for the wireless device, a last known network connection of the wireless device can be stored in the communication system. For example, a controller node, such as a mobility management entity or other controller element of the communication system, can store a last known access node with which the wireless device was in communication. Further, access nodes can be organized into groups of access nodes which can be used to send a notification to the wireless device in the event that the wireless device cannot be located at the last known access node. Examples of such access node groups comprise a tracking area and a routing area.
Overview
In operation, a number of tracking area update messages based on a transition of wireless devices from a first access node associated with a first tracking area to a second access node associated with a second tracking area are monitored. When the number of tracking area update messages meets a threshold, the association of the first access node is changed to the second tracking area. In an embodiment, the association of the first access node can also be changed based on the mobility of wireless devices from the first access node to the second access node. In an embodiment, the association of the first access node can also be changed based on determined first and second channel loads of the first and second access nodes.